Lock-alarm combination

ABSTRACT

A chained bolt door fastener and alarm system has alarm energizing electrical contacts which are actuated to sound the alarm by movement of the slidable chain bolt from an initial preset position when an attempt is made by an intruder to open the door from the outside. The contacts and the bolt may be so arranged in relation to the slide that unauthorized movement of the bolt either in the direction to permit limited opening of the door, or in the opposite direction to enable removal of the bolt from the slide, will energize the alarm.

United States Patent Inventor Paul L. Bet:

1113 Angonne Drive, Baltimore, Md. 21218 Appl. No. 724,981 Filed Apr. 29, 1968 Patented Mar. 9, 1971 LOCK-ALARM COMBINATION 3 Claims, 2 Drawing Figs. US. Cl 340/274, 1 16/14 Int. Cl G08b 13/08 Field of Search 340/274, 276, 283; 116/14; ZOO/61.67, 61.68

References Cited UNITED STATES PATENTS 521,239 6/1894 Hoopes ZOO/61.68 4/1876 Linnard 116/14 587,377 8/1897 Sutton 116/14. 2,721,239 10/1955 Kuffer 340/276 FOREIGN PATENTS 621,453 5/1927 France ZOO/61.68 367,268 l/l922 Germany.... ZO /61.68 636,985 12/1947 England 340/274 Primary Examiner-John W. Caldwell Assistant Examiner-Scott F. Partridge Attorney-Cameron, Kerkam & Sutton truder to open the door from the outside. The contacts and the bolt may be so arranged in relation to the slide that unauthorized movement of the bolt either in the direction to permit limited opening of the door, or in the opposite direction to enable removal of the bolt from the slide, will energize the alarm.

Patented Match 9, 1971 3,569,950

INVENTOR LOCK-ALARM COMBINATION This invention relates to a lock-alarm combination and has for one of its objects the provision of an effective and practical combined closure fastener and alarm which is operated by the closure fastener when the fastener is moved from an initial position.

One of the objects of the present invention is to combine a chained bolt door fastener with an alarm such that an attempt to open the door will cause the chained bolt to move from an initial preset position, thereby actuating electrical contacts in the circuit of an alarm .device, the actuation of said electrical contacts being noncancelable from the outside upon reclosure of the door but cancelable and controllable from the inside.

Another object of the present invention is to provide a chained bolt door fastener alarm system such that when the chained bolt is placed in a preset position in its slide and the system is made operative, movement of the chain bolt in either direction from this position, i.e. toward limited opening of the door or toward removal of the bolt from its slide, results in actuation of electrical contacts and energizing of the alarm device.

These and other objects will appear more fully upon consideration of the following detailed description of one embodiment of the invention which has been illustrated in the accompanying drawings. lt is to be expressly understood, however, that this description and drawings are exemplary only and are not to be construed as defining the limits of the invention, for which latter purpose reference should be had to the appended claims.

In the drawings, wherein like reference characters refer to like parts through the several views:

FIG. 1 is a front elevation view of a portion ofa door and its frame having applied thereto a closure fastener and alarm (shown diagrammatically) according to the invention; and

FIG. 2 is a sectional view taken on line 2-2 of FIG. 1.

Referring now to FIGS. 1 and 2, portions are indicated of a door and a frame member 11, said frame 11 being opposite the free side 12 of the door; the door being hinged at its opposite side in the usual manner. Secured to frame member 11 by means of screws 13 is an anchor plate 14 having a perimetric flange 15 to provide a space16 between the underside of plate 14 and frame 11. The upper end of plate 14 is provided with a slot 17. Secured to plate 14 as by means-of a looped member 18 is a flexible member in the form of a chain 19 to which is pivoted, by means of another loop member 20, a bolt 21 having an annular groove 22 and an enlarged head portion 23. Slot 17 in anchor plate 14 is adapted to receive groove 22 in bolt 21 when the latter is notin use to fasten the door. Secured to door 10 opposite plate 14 by means of screws 25 is a keeper member a slide comprising a frame 26 having a perime'tric flange 27 which provides a space 30 between the underside of frame 26 and an electrically insulating baseplate 28, yet to be described.

Frame 26 is provided with a slot 31, having a portion 31A of enlarged diameter and adapted to receive the enlarged head portion 23 of bolt 21, the remaining portion of cam slot 31 being of reduced width to accommodate the annular groove 22.

The description to this point is mainly that of chain door fasteners in general use. A departure therefrom is the inclusion of baseplate 28 which in this embodiment is interposed between frame 26 and door 10, but which, if desired, may be encompassed by flange 27 and be incorporated as a unit within frame 26. Baseplate 28 is adapted to provide a mounting means for electrical contacting members that are actuated by movement of bolt 21 in slot 31 and its associated enlarged head or cam portion 23. A resilient conducting blade arm 40, having an electrical contact 41 at one end, is supported at its other end in spaced relationship to baseplate 28. A spacer 42 and rivet 43 arrangement is illustrated for supporting arm but other suitable means may be employed. Arm 40 is provided intermediate of its extremities with a cam 52 which is adapted to engage cam portion 23 of bolt 21. Cooperating with contact 41 is an electrical contact 51 which is supported by conducting arm 50 and mounted on baseplate 28 in any suitable manner as by rivets 45. Contacts 41,51, are normally closed. Lead 44 is connected to arm 40 and lead 54 is connected to ,arm 50. Contacts 41,51 are held open when earns 23 and 52 are'in engagement as shown in FIG. 2. When bolt 21 is moved in either direction away from the position shown in FIGS. 1 and 2 cams 23,52 disengage and contacts 41,51 return to their normally closed position maintained by resilient contact arm 40, thereby completing the electrical circuit between leads 44 and 54.

FIG. 1 indicates diagrammatically at an alarm arrangement having terminals 75,76 Normally closed contacts are indicated at 61 and 62; one of said contacts 62 being fixed and the other contact 61 being supported on a resilient contact arm .63 the latter having a cam portion 64. Cooperating with cam portion 64 is a pin-type key 65 which in the position shown in FIG. 1 is out of engagement with cam portion 64. When key 65 is fully inserted in its guide 66 key 65 engages cam portion 64 and separates contact 61 from its cooperating contact 62. Contact arm 63 is connected to terminal 75 by lead 74 and contact 62 is connected by lead 67 to one terminal of a battery 68. The other terminal of battery 68 is connected by lead 69 to terminal 71 of alarm device 70. Alarm device is preferably an electromagnetically driven diaphragm device, but a bell, buzzer, or other type of alarm or signalling device may be employed. The other terminal 72 of alarm device 70 is connected to terminal 76 by lead 73, v

Where a remote alarm or indication is desired leads 69,73 may be extended to the remote location and there connected to an alarm or indicating device.

As shown in FIGS. 1 and 2 cams 23,52 are engaged thereby separating contacts 41,51, and key 65 is in its withdrawn position permitting contacts 61,62 to be closed. These conditions are for the case where the lock-alarm is operative. Should an intruder open the door the tension in chain 19 causes bolt 21 to be pulled to the left as viewed in the FlGSand separation of cams 23,52 results in the closure of contacts 41,51. Alarm 70 is thereby energized through the circuit which includes terminal 76, lead 54, arm 50, contacts 51 and 41, arm 40, lead 44, terminal 75, lead 74, arm 63, contacts 61 and 62, lead 67, battery 68, lead 69, alarm 70, and lead 73 to terminal 76. It is to be noted that once bolt 21 is pulled to the left as viewed in the FIGS. in an attemptto openthe door subsequent closure of the door from the outside will not cause contacts 41,51 to open and alarm 70 will continue to operate. The alarm can be silenced only from the inside either by restoring bolt 21 to its original position in which cams 23,52 are in engagement thereby separating contacts 41,51 or by fully inserting key 65 and thereby separating contacts 61,62.

The alarm is similarly actuated by movement of bolt 21 to the right from its original position viewed in FIGS. 1 and 2. Movement to the right would be required to remove bolt 21 from slot 31 and would be in the direction of the enlarged diameter portion 31A of slot 31. Operation of the alarm in this situation is desirable where the lock-alarm combination is applied to a door having a glass portion through which an intruder might attempt to remove bolt 21 from its slot 31. For this application key 65should be removed completely from its guide 66 thus making it impossible to circumvent the sounding of alarm 60 or alarm 60 may be made inaccessible. Again, the alarm will operate continuously when bolt 21 is removed from slot 31. From inside the house the alarm may be shut off by fully inserting key 65 or by restoring bolt 21 to its cam actuating position.

Although only one structural embodiment of the invention has been described herein, it is to be expressly understood that this disclosure is intended for purposes of illustration only and that the invention is capable of embodiment in other forms. Various modifications, which will now suggest themselves to those'skilled in the art, may be made in the mechanical con struction and configuration of the electrical contact arrange ment associated with the chain bolt without departing from the inventive concept. Reference is therefore to be had to the appended claims for a definition of the limits of the invention.

lclaim:

l. A chained bolt door fastener and alarm system of the type comprising a keeper member mounted on a door and having an elongated slot therein, a flexible chain having one end secured to a structural part adjacent said door and a bolt connected to the other end thereof, said bolt being adapted for insertion in and slidable movement along said slot, and an electrically energized alarm system adapted to be actuated when said bolt is moved from a predetermined position in said slot due to an attempt to open the door from the outside, wherein the alarm system includes an electrical energizing circuit having a pair of normally closed contacts mounted within said keeper member, one of said contacts being carried by an elongated resilient contact arm mounted substantially parallel to and spaced from the path of movement ofsaid bolt in said slot, said contact arm having a portion thereof intermediate its length which extends into the path of movement of said bolt for engagement thereby when the bolt is in a predetermined position intermediate the length of said slot, whereby said contacts are held open when said bolt is in said predetermined position and are closed automatically and are maintained closed, by the resilience of said arm when said bolt is displaced from said position in either direction.

2. A chained bolt door fastener and alarm system according to claim 1, wherein the portion of said resilient contact arm which extends into the path of movement of said bolt is a cam fixed to said arm, and said bolt includes a cooperating cam portion.

3. A chained bolt door fastener and alarm system according to claim 1, wherein the electrical energizing circuit of said alarm system includes a second pair of normally closed contacts, and a manually operable switch for opening said second pair of contacts when the alarm system is to be rendered inoperative, 

1. A chained bolt door fastener and alarm system of the type comprising a keeper member mounted on a door and having an elongated slot therein, a flexible chain having one end secured to a structural part adjacent said door and a bolt connected to the other end thereof, said bolt being adapted for insertion in and slidable movement along said slot, and an electrically energized alarm system adapted to be actuated when said bolt is moved from a predetermined position in said slot due to an attempt to open the door from the outside, wherein the alarm system includes an electrical energizing circuit having a pair of normally closed contacts mounted within said keeper member, one of said contacts being carried by an elongated resilient contact arm mounted substantially parallel to and spaced from the path of movement of said bolt in said slot, said contact arm having a portion thereof intermediate its length which extends into the path of movement of said bolt for engagement thereby when the bolt is in a predetermined position intermediate the length of said slot, whereby said contacts are held open when said bolt is in said predetermined position and are closed automatically and are maintained closed, by the resilience of said arm when said bolt is displaced from said position in either direction.
 2. A chained bolt door fastener and alarm system according to claim 1, wherein the portion of said resilient contact arm which extends into the path of movement of said bolt is a cam fixed to said arm, and said bolt includes a cooperating cam portion.
 3. A chained bolt door fastener and alarm system according to claim 1, wherein the electrical energizing circuit of said alarm system includes a second pair of normally closed contacts, and a manually operable switch for opening said second pair of contacts when the alarm system is to be rendered inoperative. 